2UDP

UDP-GALACTOSE 4-EPIMERASE COMPLEXED WITH UDP-PHENOL


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Work: 0.186 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

High-resolution X-ray structure of UDP-galactose 4-epimerase complexed with UDP-phenol.

Thoden, J.B.Frey, P.A.Holden, H.M.

(1996) Protein Sci 5: 2149-2161

  • DOI: 10.1002/pro.5560051102
  • Primary Citation of Related Structures:  
    2UDP

  • PubMed Abstract: 
  • UDP-galactose 4-epimerase from Escherichia coli catalyzes the interconversion of UDP-glucose and UDP-galactose. In recent years, the enzyme has been the subject of intensive investigation due in part to its ability to facilitate nonstereospecific hydride transfer between beta-NADH and a 4-keto hexopyranose intermediate ...

    UDP-galactose 4-epimerase from Escherichia coli catalyzes the interconversion of UDP-glucose and UDP-galactose. In recent years, the enzyme has been the subject of intensive investigation due in part to its ability to facilitate nonstereospecific hydride transfer between beta-NADH and a 4-keto hexopyranose intermediate. The first molecular model of the epimerase from E. coli was solved to 2.5 A resolution with crystals grown in the presence of a substrate analogue, UDP-phenol (Bauer AJ, Rayment I, Frey PA, Holden HM, 1992, Proteins Struct Funct Genet 12:372-381). There were concerns at the time that the inhibitor did not adequately mimic the sugar moiety of a true substrate. Here we describe the high-resolution X-ray crystal structure of the ternary complex of UDP-galactose 4-epimerase with NADH and UDP-phenol. The model was refined to 1.8 A resolution with a final overall R-factor of 18.6%. This high-resolution structural analysis demonstrates that the original concerns were unfounded and that, in fact, UDP-phenol and UDP-glucose bind similarly. The carboxamide groups of the dinucleotides, in both subunits, are displaced significantly from the planes of the nicotinamide rings by hydrogen bonding interactions with Ser 124 and Tyr 149. UDP-galactose 4-epimerase belongs to a family of enzymes known as the short-chain dehydrogenases, which contain a characteristic Tyr-Lys couple thought to be important for catalysis. The epimerase/NADH/UDP-phenol model presented here represents a well-defined ternary complex for this family of proteins and, as such, provides important information regarding the possible role of the Tyr-Lys couple in the reaction mechanism.


    Organizational Affiliation

    Institute for Enzyme Research, Graduate School, University of Wisconsin, Madison 53705, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
UDP-GALACTOSE 4-EPIMERASEA, B338Escherichia coliMutation(s): 0 
EC: 5.1.3.2
UniProt
Find proteins for P09147 (Escherichia coli (strain K12))
Explore P09147 
Go to UniProtKB:  P09147
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAD
Query on NAD

Download Ideal Coordinates CCD File 
C [auth A], F [auth B]NICOTINAMIDE-ADENINE-DINUCLEOTIDE
C21 H27 N7 O14 P2
BAWFJGJZGIEFAR-NNYOXOHSSA-N
 Ligand Interaction
UPP
Query on UPP

Download Ideal Coordinates CCD File 
D [auth A], G [auth B]PHENYL-URIDINE-5'-DIPHOSPHATE
C15 H18 N2 O12 P2
ZHUWBKDWWGKIEN-FMKGYKFTSA-N
 Ligand Interaction
EDO
Query on EDO

Download Ideal Coordinates CCD File 
H [auth B]1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
NA
Query on NA

Download Ideal Coordinates CCD File 
E [auth B]SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Work: 0.186 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 76α = 90
b = 78.7β = 90
c = 128.6γ = 90
Software Package:
Software NamePurpose
TNTrefinement
XSCALIBREdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1998-03-18
    Type: Initial release
  • Version 1.1: 2008-03-25
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2015-05-27
    Changes: Structure summary